Process for the manufacture of phosphorus oxychloride and thionyl chloride



D M 9 G E 5 Nm m 9 mC on o0.. MA U w oo 8, TC L ma 7 Nl| N .IE 1, 9 ww .I mm W Q 5R S um L P. WA U U. A of .5 w D H PE 5U SD .O01 016 H| R PL mmm 5 Fw L.8 ,7 EEul f R www HCIo cmmN SWDM F .ANI GMA .Eml Jwla Rn ROi 0mm dm s c 0 R P JOHN QEOIZQE SGHUDEL INVENTQR Patented Jan. 13, 1931 Unirse 'rar-as riaaase Parana Fri' JOHN GEORGE SCHUDEL, OF NITRO, WEST VIRGINIA, ASSIGNOR TO THE ELKO CHEMICAL COMPANY, OF NITRO, WEST VIRGINIA, A CORPORATION OF WEST VIRGINIA PROCESS FOR THEMANUFACTURE continuation in part of ppiiczaion semi No. 149,063, sied iiQvQia, i926.

i Y 1 3, 1928. Serial No. 285,140.

My invention relates vparticularly to a V)rocess of makin0- hos nhorus ox chloride and thionyl chloride, and has relation especially to the manufacture thereof with the aid of chlorine and sulphur dioxide.

Both phosphorusoxycliloride and thionyl chloride are becoming of increased impor'-` for example, the oxidation of phosphorus trichloride with potassium chlorate (Jour. f.

pr. Chemie, 1883, (2) Vol. 23, p. 382).; the reaction Vbetween pentachloride and water (G. Oddo, Gr. 25, II, p. 330) b-y passing' chlorine over heated calcium metaphosphate and coal (German Patent 138,392) the reaction of phosgene upon calcium phosphate (U. S.

Patent 1,424,193); by passing sulphur vdi-V oxide gas over phosphorus pentachloride (Annalen 102; 111, 1857) v; the react-ion of sulphuryl chloride with phosphorus trichloride (German Patent 415,312). Also, it has been proposed to make thionyl Ychloride byv the action of sulphur dioxide gas on phosphorus pentachloride (Schiff, Annalen, 102, page 111, 1857), which however', gives only of the theoretical quantity (Vanino, Praep. Chemie, I, p. 94); or the action of sulphuryl chloride on phosphorus trichloride (German Patent 415,312) the interaction of sulphur trioxide, sulphur chloride and chlorine (German Patent 139,455) the reaction between sulphuryl chloride and carbon monoxide, or pliosgene and sulphur dioxide (German Patent 284,935).

All of these previous processes for producing these two compounds are, however, complicated and expensive. For example, phosphorus pentachloride is expensive and its in-V teraction with sulphur dioxide is slow and produces, furthermore, a p-oor yield. rlhe products obtained from phosphorus trichloride and sulphuryl chloride are di'icult to O 'E IPI-IOSPHORUSr OXYCHLORIDE AND THIONYL- CHLORIDE separate in View of the'boiling Apoints,ithe

thioiiyl chloride Z8-79o C., and phosphorus Ox'ychloride 107o C,

I have found that when chlorineand sulfur dioxide are mixed together, kas herein after referred to in carrying out the desired reaction, and used simultaneously either as VThis reaction isinstanta eous and qua-n-v titative. Y

In carrying out theV present invention, it

has been found thatthelpliosphorus trichloride could be present `in any desired excess when'using sulfur dioxide and chlorine in thep'roper ratio, the 'only products obtained' being phosphorus. oxychloridefand tl'iionyil chloride. V`The rate of the reaction is controlled by the amount of external cooling applied',a nd the reaction may be carried out in an open container unless it is conducted at a temperature above theboiling point of thionyl chloride, lin which Vcase a reflux condenser may be attached, or the thionyl chloride maybe distilled off as formed.

My prior application upon liquefied'gascs and processof using the same, executed on the 29th nday of September, 1926, is related generically to the presentinvention, and is Serial No. 140,427, filed @ctober 8, 1926.

vWhile Vmyv invention is capable of embodiment in many different fornis,-I have de? scribed oniy certain forms of the same'in de-f tail hercin, and while it is capable of being carriedout in many different types of appa ratus, I have shown only one type of apparatus for use in connection therewith in the' the reflux condenser may-be' omitted, as above pointed out.

This application filed Junev F or example, in carrying out my invention I may introduce liquid suliur dioxide into a sulfur dioxide and chlorine mixing chamber 1 by means ot' a pipe 1a, and thereafter VI may tntroduce liquid chlorine into the same. An outlet pipe 2 is provided from the vessel 1, which discharges into a phosphorus trichloride and liquid carrier 3 beloiv the surface ot the liquid therein. `The phosphorus trichlo- 'idc and liquid carrier 3 may have a cooling jacket 3a provided with a current yo'f'cooling water by means of inlet and out-let pipes 3b and 3c. Said phosphorus trichloride and liquid carrier 3 also has a charging hole 3d and valved drain pipe 3e, as well as a thermorneter 3f. It desired, the liquid sulfur dioxide and chlorine may be allowed to expand prior v to entering the phosphorus trichloride and liquid carrier 3 before the reaction, but pret- `:rably the mixed liquids which form -a solu- Ytion are introduced directly into the contents of the phosphorus trichloride and liquid carrier 3 in order to utilize the cooling effect of the same. As a result, a lively reaction'ensues .vhich is controlled by adjusting the amount of mixed liquid gases fed into the same and the amount of external cooling applied. The end of the reaction may be observed by one or moreV of the -following conlitions Ardistinct fall in temperature and /or by cessationv of the complete absorption of the mixed gases or liquids. In case the above reaction is conducted at a temperature above the boiling point ot thionyl chloride, the phos-Y ,-horus trichloride andliqnid carrier 3 will have provided thereon areflux condenser 4 connected to the "phosphorus trichloride and liquid carrier 3 by a pipe 4a, the'condenser beinecooled by a` current of Water provided by inlet and out-let pipes and 6, respectively, which lat-ter is connected to the outlet pipe 30, leading from tbe phosphorus trichloride and liquid carrier jacket. From the reflux condenser 11 an outlet pipe 7 passes into a trap 8 ontaining sulfuric acid and having a vent pipe 9. After the :reaction product has thus been obtained, the components of? the reaction mixture may be separated by fractional distillation inan efficient column.

It will be understood that many changes may be made in the proportion of the materials above used, as Well as the order in which they are introduced, and the temperatures under which the reactions are conducted, ctc. llhe preferred method of practicing the invention, however, comprises the reaction between substantially equimolecular propor tions of phosphorus trichloride, sulfur dioxide and chlorine as indicated in the equation .iereinbefore stated.

This case is a continuation in part of application Serial No. 149,063, filed November 18, 1926, by the present applicant which Was isgspd as Patent No. 1.753.? 514, dated April 8, L Q D meseta IVhat is claimed is:

1. rlhe process which comprises producing phosphorus oxychloride and thionyl chloride by the reaction of a mixture of sulfur dioxide and chlorine on phosphorus trichloride."

2. The process which 'comprises producing phosphorus oxychloride andA thionyl chloride by the reaction of a mixture of sulfur dioxide and chlorine on phosphorus trichloride, the sulfur dioxide and chlorine being in the torni ot' a liquid.

3. The process Which comprises producing phosphorus oxychloride and thionyl chloride by the reaction bet-Ween substantially equi; moleculaiproportions of sulfur dioxide, chlorine and phosphorus trichloride.

f1. The process Which comprises producing phosphorus oxychloride and thionyl chlo-A ride by the reaction between substantially equimolecnlar proportions of sulfur dioxide, chlorine and phosphorus trichloride, said reacting constituents being in the liquid phase.

In testimony whereof I hereunto aliix my signature. f

JOHN GEORGE SCI-IUDEL. 

